Fertility Treatment and the Chances of Twins

If you are having trouble conceiving and start to have fertility treatment, your doctor or someone in your medical team will probably have a chat with you at some point about multiple births. All types of multiple births are more common if you are taking a fertility drug such as Clomid, as this increases the chances that you will ovulate regularly, and that you will produce more than one egg during a single menstrual cycle.

The chances of twins, triplets, quadruplets or even more multiple births when having IVF used to be much higher when the technique was still being developed. This is because more than one fertilised egg was always placed into the woman’s uterus, to try to give her the best possible chance of becoming pregnant. When the procedure was at its most successful, more than one of the embryos would implant and grow. In recent years, the technique has become more successful generally, and now it is usual for only two embryos to be introduced, rather than more. This increases the chances of twins with IVF, but larger numbers of babies born at once are now much rarer.

Statistics on Multiple Births and Fertility Treatment

The statistics collected on the number of multiple births that occurred before and after 1978, when the IVF procedure was first done show a huge increase in twin births. The number of couples having twins has increased by 65% since the early 1980s and today, about one in every 32 live births involves the delivery of twins. If only women who conceive naturally are studied, the rate of twin births is much lower than the average (in every 89 births), as average data includes women having fertility treatments.

In the two decades after 1978, the rate of multiple births of more than two babies shot up by something like 400% - solely due to the increase in births due to IVF. This rate has now fallen again, although there are still cases of 6, or even 8 babies being born at once, in women who take fertility drugs like Clomid or gonadotrophins. Here there is no artificial control of the number of eggs released and as there are so many sperm in excess, the risk of having multiple siblings that are not identical, but that are born at the same time, is much higher.

Considering Twins

If you are having fertility treatment, there is no way to know what is going to happen. Once you are pregnant, you will be offered an ultrasound scan, sometimes as early as 12 weeks, and it will be obvious that you are going to have twins this early in your pregnancy when you see the scan images. Before that it is important to consider the possibility and prepare so that this is not so much of a shock.

During the rest of your pregnancy you need to prepare emotionally and practically for the birth, and for the days, weeks and months afterwards. Once twins reach a certain age – probably when they become toddlers, the workload and stress of looking after two babies diminishes and parents find the times after that similar to having children of different ages who are born reasonably close together. The difficult time is the first year or so, and it is a good idea to see if you can get other members of the family to help during that time. Having one baby that wakes at night for feeding and changing is tiring enough, but two babies at once needs even more resilience and organisation – and a few more helping hands.

Fertility Treatments and the Future Risk of Twins

As long as fertility drugs are used, and IVF techniques introduce more than one embryo, the chances of having twins will continue to be greater if you have fertility treatments. Currently, there are no plans to only introduce one embryo during IVF as this would reduce the success rate significantly.